WSET.com - ABC13Summer Winding Down by Matt Ferguson

Many of you are probably ready to see the summer of 2010 come to a close, as it ended up being a scorcher. In fact, it was the hottest on record in Blacksburg, Danville and Roanoke and the 7th hottest in Lynchburg. The summer seasons between the end of El Nino and beginning of La Nina often bring very hot weather to the eastern part of the United States. Of course, that happened this year with the changing of Pacific Ocean temperatures from above normal (El Nino) to below normal (La Nina). Therefore, the extreme heat was probably NOT because of global warming. It will be interesting to see if the world begins a net cool down during the next 2 years, as some of the information is now showing. It's all about sunspots and natural global oscillations that bring 11 year cycles of weather change.

So after talking about all the heat, let's chat about some cooler weather. Our Labor Day Weekend turned out amazing, with pleasant afternoons and cool nights. Sunday (9/5/10) morning's low hit 47 in Lynchburg, so definitely a little taste of autumn here. By the way, fall begins this year on September 23rd! My grandfather constantly kept records of the weather in his backyard. He would always tell me September brings cooler and less muggy nights. While late summer afternoon sunshine keeps things warm, the nights become much longer allowing more cooling overnight. Right now, we are losing about 2.5 minutes of sunlight each day. When there is optimal cooling conditions it can really get chilly across our region. In Lynchburg on September 29, 1942, we hit an all time record low for the month of 35 degrees. This brought patchy frost to our area. These chilly nights usually occur about 36 to 48 hours after the passage of an early autumn cool front. This is when we see the best radiational cooling conditions. Radiational cooling is when you have clear skies, low humidity and calm winds. Also longer nights further promote cooling. With each passing day we'll see much more of these cooling processes take place. With all the heat we have had to endure this past summer, we certainly deserve the upcoming refreshing fall weather. Get outside and enjoy mother nature's air conditioning.